Moisture-Stable FAPbI₃ Perovskite Achieved by Atomic Structure Negotiation

Area of Science:

• Materials Science
• Solid-State Physics
• Renewable Energy

Background:

• Formamidinium lead iodide (FAPbI3) perovskites are promising for solar cells but suffer from phase transitions at working temperatures.
• Existing methods to stabilize FAPbI3 perovskites have had limited success in addressing the core issue of phase instability.

Purpose of the Study:

• To develop a novel strategy for stabilizing the FAPbI3 perovskite structure against phase transitions.
• To enhance the moisture and structural stability of FAPbI3 perovskite solar cells.

Main Methods:

• Incorporation of water molecules into the FAPbI3 perovskite structure using a new structural physics approach.
• Relocation of secondary bonding within the perovskite structure to alter its microstructure.
• Analysis of internal strain and its effect on phase transitions.

Main Results:

• Achieved a tenfold enhancement in moisture and structural stability of the FAPbI3 perovskite.
• Maintained a bandgap comparable to the favored α-FAPbI3 phase.
• Successfully altered the microstructure by relocating secondary bonding, mitigating internal strain.

Conclusions:

• The incorporation of water molecules offers an unprecedented strategy for stabilizing FAPbI3 perovskites.
• This method effectively resolves the undesirable phase transition issue, enhancing material durability.
• The findings present a significant advancement for perovskite solar cell research and the broader materials community.